Nuclear weapon yield
Encyclopedia
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
discharged when a nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
is detonated, expressed usually in the equivalent mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of trinitrotoluene (TNT), either in kilotons (thousands of tons of TNT) or megatons
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
(millions of tons of TNT), but sometimes also in terajoules (1 kiloton of TNT = 4.184 TJ). Because the precise amount of energy released by TNT is and was subject to measurement uncertainties, especially at the dawn of the nuclear age, the accepted convention is that one kt of TNT is simply defined to be 1012 calorie
Calorie
The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat, entering French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule...
s equivalent, this being very roughly equal to the energy yield of 1,000 tons of TNT.
The yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon. The theoretical maximum yield-to-weight ratio for fusion weapons (thermonuclear weapons) is 6 megatons of TNT per metric ton of bomb mass (25 TJ/kg). Yields of 5.2 megatons/ton and higher have been reported for large weapons constructed for single-warhead use in the early 1960s. Since this time, the smaller warheads needed to achieve the increased net damage efficiency (bomb damage/bomb weight) of multiple warhead systems, has resulted in decreases in the yield/weight ratio for single modern warheads.
Examples of nuclear weapon yields
In order of increasing yield (most yield figures are approximate):| Bomb | Yield | Notes | |
|---|---|---|---|
| kt TNT | TJ | ||
| Davy Crockett Davy Crockett (nuclear device) The M-28 or M-29 Davy Crockett Weapon System was a tactical nuclear recoilless gun for firing the M388 nuclear projectile that was deployed by the United States during the Cold War... |
0.01 ktTNT | Variable yield Variable yield Variable yield — or dial-a-yield — is an option available on most modern nuclear weapons. It allows the operator to specify a weapon's yield, or explosive power, allowing a single design to be used in different situations... tactical nuclear weapon—mass only 23 kg (51 lb), lightest ever deployed by the United States (same warhead as Special Atomic Demolition Munition Special Atomic Demolition Munition The Special Atomic Demolition Munition was a family of man-portable nuclear weapons fielded by the US military in the 1960s, but never used in actual combat. The US Army planned to use the weapons in Europe in the event of a Soviet invasion... and GAR-11 Nuclear Falcon missile AIM-26 Falcon The AIM-26 Falcon was a larger, more powerful version of the AIM-4 Falcon air-to-air missile built by Hughes. It is the only guided U.S. air-to-air weapon with a nuclear warhead, though the unguided AIR-2 Genie was also nuclear-armed.-Development:... ). |
|
| Hiroshima's | 12 ktTNT | Gun type uranium-235 Uranium-235 - References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the... fission bomb (the first of the two nuclear weapons that have been used in warfare). |
|
| Nagasaki's gravity bomb | 20 ktTNT | Implosion type plutonium-239 Plutonium-239 Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in... fission bomb (the second of the two nuclear weapons used in warfare). |
|
| W76 W76 The W76 is a United States thermonuclear warhead. It was manufactured from 1978-1987, and is still in service .The W-76 is carried inside a Mk-4 re-entry vehicle. U.S... warhead |
100 ktTNT | Twelve of these may be in a MIRVed Trident II missile Trident missile The Trident missile is a submarine-launched ballistic missile equipped with multiple independently-targetable reentry vehicles . The Fleet Ballistic Missile is armed with nuclear warheads and is launched from nuclear-powered ballistic missile submarines . Trident missiles are carried by fourteen... ; treaty limited to eight. |
|
| W87 W87 The W87 is an American thermonuclear missile warhead. It was created for use on the MX or Peacekeeper ICBM, 50 of which, with up to 12 warheads per missile, were deployed during the 1986-2005 period... warhead |
300 ktTNT | Ten of these were in a MIRVed LGM-118A Peacekeeper LGM-118A Peacekeeper The LGM-118A Peacekeeper, also known as the MX missile , was a land-based ICBM deployed by the United States starting in 1986. A total of 50 missiles were deployed. They have since been deactivated.... . |
|
| W88 W88 The W88 is a United States thermonuclear warhead, with an estimated yield of 475 kiloton , and is small enough to fit on MIRVed missiles. The W88 was designed at the Los Alamos National Laboratory in the 1970s. In 1999 the director of Los Alamos who had presided over its design described it as... warhead |
475 ktTNT | Twelve of these may be in a Trident II missile (treaty limited to eight). | |
| Ivy King Ivy King Ivy King was the largest pure fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy... device |
500 ktTNT | Most powerful pure fission bomb, 60 kg uranium, implosion type. | |
| B83 nuclear bomb B83 nuclear bomb The B83 nuclear weapon is a variable yield gravity bomb developed by the United States in the late 1970s, entering service in 1983. With a maximum yield of 1.2 megatons, it is currently the most powerful atomic weapon in the US arsenal... |
variable | Up to 1.2 MtTNT; most powerful US weapon in active service. | |
| B53 nuclear bomb B53 nuclear bomb The Mk/B53 was a high-yield bunker buster thermonuclear weapon developed by the United States during the Cold War. Deployed on Strategic Air Command bombers, the B53, with a yield of , was the most powerful weapon in the U.S... |
9000 ktTNT | Was the most powerful US bomb until 2010; it was not in active service for many years before 2010, but during that time, 50 were retained as part of the "Hedge" portion of the Enduring Stockpile Enduring Stockpile The "Enduring Stockpile" is the United States's arsenal of nuclear weapons following the end of the Cold War.During the Cold War the United States produced over 70,000 nuclear weapons. By its end the U.S. stockpile was about 23,000 weapons of 26 different types... until completely dismantled in 2011, a variant of the two-stage B61 B61 B61 may refer to :* B61 nuclear bomb* B61 in Brooklyn* HLA-B61, an HLA serotype* Sicilian, Richter-Rauzer, Larsen variation, 7.Qd2, according to the list of chess openings* an alternative name for the ephrin A1 human gene... is the B53 B53 B53 or B-53 may refer to :* B53 nuclear bomb* HLA-B53, an HLA-B serotype* Convair XB-53, an American aircraft... replacement in the bunker-busting role; the B53 B53 B53 or B-53 may refer to :* B53 nuclear bomb* HLA-B53, an HLA-B serotype* Convair XB-53, an American aircraft... was similar to the W-53 warhead that has been used in the Titan II Missile; decommissioned in 1987. |
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| Castle Bravo Castle Bravo Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,... device |
15000 ktTNT | Most powerful US test. | |
| EC17/Mk-17, the EC24/Mk-24, and the B41 B41 nuclear bomb The B41 was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States with a theoretical maximum yield of 25 megatons... (Mk-41) |
various | Most powerful US weapons ever: 25 MtTNT; the Mk-17 was also the largest by size and mass: about 20 short tons (18,143.7 kg); The Mk-41 or B41 B41 nuclear bomb The B41 was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States with a theoretical maximum yield of 25 megatons... had a mass of 4800 kg and yield of 25Mt, this equates to being the highest yield-to-weight weapon ever produced; all were gravity bombs carried by the B-36 bomber (retired by 1957). |
|
| The entire Operation Castle Operation Castle Operation Castle was a United States series of high-energy nuclear tests by Joint Task Force SEVEN at Bikini Atoll beginning in March 1954... nuclear test series |
48200 ktTNT | The highest-yielding test series conducted by the US. | |
| Tsar Bomba Tsar Bomba Tsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. It was also referred to as Kuz'kina Mat , in this usage meaning "something that has not been seen before".... device |
50000 ktTNT | USSR, most powerful nuclear weapon ever detonated, mass of 50 megatons, (50 million tons of tnt). In its "full" form (i.e. with a depleted uranium Depleted uranium Depleted uranium is uranium with a lower content of the fissile isotope U-235 than natural uranium . Uses of DU take advantage of its very high density of 19.1 g/cm3... tamper instead of one made of lead Lead Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed... ) it would have been 100 MtTNT. |
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| All nuclear testing Nuclear testing Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them... as of 1996 |
510300 ktTNT | Total energy expended during all nuclear testing.http://books.google.com/books?id=xAwAAAAAMBAJ&pg=PA63&dq=510.3&as_pt=MAGAZINES&ei=0VpnSuGLLoWQNuSdnaAB | |
GBU-43 Massive Ordnance Air Blast bomb
The GBU-43/B Massive Ordnance Air Blast bomb is a large-yield conventional bomb developed for the United States military by Albert L. Weimorts, Jr. At the time of development, it was touted as the most powerful non-nuclear weapon ever designed...
is 0.011 kt, and that of the Oklahoma City bombing
Oklahoma City bombing
The Oklahoma City bombing was a terrorist bomb attack on the Alfred P. Murrah Federal Building in downtown Oklahoma City on April 19, 1995. It was the most destructive act of terrorism on American soil until the September 11, 2001 attacks. The Oklahoma blast claimed 168 lives, including 19...
, using a truck-based fertilizer bomb, was 0.002 kt. Most artificial non-nuclear explosions are considerably smaller than even what are considered to be very small nuclear weapons.
Yield limits
The yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon. The theoretical maximum yield-to-weight ratio for fusion weapons is 6 megatons of TNT per metric ton (25 TJ/kg). The practical achievable limit is somewhat lower, and tends to be lower for smaller, lighter weapons, of the sort that are emphasized in today's arsenals, designed for efficient MIRV use, or delivery by cruise missile systems.- The 25 Mt yield option reported for the B41B41 nuclear bombThe B41 was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States with a theoretical maximum yield of 25 megatons...
would give it a yield-to-weight ratio of 5.2 megatons of TNT per metric ton. While this would require a far greater efficiency than any other current U.S. weapon (at least 40% efficiency in a fusion fuel of lithium deuteride), this was apparently attainable, probably by the use of higher than normal Lithium-6Isotopes of lithiumNaturally occurring lithium is composed of two stable isotopes, and , the latter being the more abundant...
enrichment in the lithium deuteride fusion fuel. This results in the B41B41 nuclear bombThe B41 was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States with a theoretical maximum yield of 25 megatons...
still retaining the record for the highest Yield-to-weightEnergy densityEnergy density is a term used for the amount of energy stored in a given system or region of space per unit volume. Often only the useful or extractable energy is quantified, which is to say that chemically inaccessible energy such as rest mass energy is ignored...
weapon ever made.
- In 1963 DOE declassified statements that the U.S. had the technological capability of deploying a 35 MT warhead on the Titan II, or a 50-60 MT gravity bomb on B-52s. Neither weapon was pursued, but either would require yield-to-weight ratios superior to a 25 MT Mk-41. This may have been achievable by utilizing the same design as the B-41 but with the addition of a HEU tamper, in place of the cheaper, but lower energy densityEnergy densityEnergy density is a term used for the amount of energy stored in a given system or region of space per unit volume. Often only the useful or extractable energy is quantified, which is to say that chemically inaccessible energy such as rest mass energy is ignored...
U-238Uranium-238Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...
tamper which is the most commonly used tamper material in Teller-Ulam thermonuclear weapons.
- For current smaller US weapons, yield is 600 to 2200 kilotons of TNT per metric ton. By comparison, for the very small tactical devices such as the Davy Crockett it was 0.4 to 40 kilotons of TNT per metric ton. For historical comparison, for Little Boy the yield was only 4 kilotons of TNT per metric ton, and for the largest Tsar BombaTsar BombaTsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. It was also referred to as Kuz'kina Mat , in this usage meaning "something that has not been seen before"....
, the yield was 2 megatons of TNT per metric ton (deliberately reduced from about twice as much yield for the same weapon, so there is little doubt that this bomb as designed was capable of 4 megatons per ton yield).
- The largest pure-fission bomb ever constructed had a 500 kiloton yield, which is probably in the range of the upper limit on such designs. Fusion boosting could likely raise the efficiency of such a weapon significantly, but eventually all fission-based weapons have an upper yield limit due to the difficulties of dealing with large critical masses. However there is no known upper yield limit for a fusion bomb.
- Because the maximum theoretical yield-to-weight ratio is about 6 megatons of TNT per metric ton, and the maximum achieved ratio was apparently 5.2 megatons of TNT per metric ton, there is a practical limit on the total yield for air-delivered weapon. Note that most later generation weapons have eliminated the very heavy casing once thought needed for the nuclear reactions to occur efficiently - this greatly increases the achievable yield-to-weight ratio. For example, the Mk-36 bomb as built had a yield-to-weight ratio of 1.25 megatons of TNT per metric ton. If the 12,000 pound casing of the Mk-36 was reduced by 2/3s, the yield-to-weight ratio would have been 2.3 megatons of TNT per metric ton, which is about the same as the later generation, much lighter 9 megaton Mk/B-53 bomb.
- Delivery size limits can be estimated to ascertain limits to delivery of extremely high yield weapons. If the full 250 metric ton payload of the Antonov An-225Antonov An-225The Antonov An-225 Mriya is a strategic airlift cargo aircraft, designed by the Antonov Design Bureau in the 1980s. It is the world's heaviest aircraft. The design, built in order to transport the Buran orbiter, was an enlargement of the successful An-124 Ruslan...
could be used, a 1.3 gigaton bomb could be delivered. Likewise the maximum limit of a missile-delivered weapon is determined by the missile payload capacity. The large Russian SS-18 ICBM has a payload capacity of 7,200 kg, so the calculated maximum delivered yield would be 37.4 megatons of TNT. A Saturn VSaturn VThe Saturn V was an American human-rated expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. A multistage liquid-fueled launch vehicle, NASA launched 13 Saturn Vs from the Kennedy Space Center, Florida with no loss of crew or payload...
-scale missile could deliver over 120 tons with a yield of about 700 megatons.
Again, it is helpful for understanding to emphasize that large single warheads are seldom a part of today's arsenals, since smaller MIRV warheads are far more destructive for a given total yield or payload capacity. This effect, which results from the fact that destructive power of a single warhead scales approximately as the 2/3 power of its yield, more than makes up for the lessened yield/weight efficiency encountered if ballistic missile warheads are scaled-down from the maximal size that could be carried by a single-warhead missile.
Calculating yields and controversy
Yields of nuclear explosionNuclear explosion
A nuclear explosion occurs as a result of the rapid release of energy from an intentionally high-speed nuclear reaction. The driving reaction may be nuclear fission, nuclear fusion or a multistage cascading combination of the two, though to date all fusion based weapons have used a fission device...
s can be very hard to calculate, even using numbers as rough as in the kiloton or megaton range (much less down to the resolution of individual terajoules). Even under very controlled conditions, precise yields can be very hard to determine, and for less controlled conditions the margins of error can be quite large. Yields can be calculated in a number of ways, including calculations based on blast size, blast brightness, seismographic data, and the strength of the shock wave. Enrico Fermi
Enrico Fermi
Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...
famously made a (very) rough calculation of the yield of the Trinity test
Trinity test
Trinity was the code name of the first test of a nuclear weapon. This test was conducted by the United States Army on July 16, 1945, in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico, at the new White Sands Proving Ground, which incorporated the Alamogordo Bombing...
by dropping small pieces of paper in the air and measuring at how far they were moved by the shock wave of the explosion.
A good approximation of the yield of the Trinity test device was obtained in 1950 from simple dimensional analysis
Dimensional analysis
In physics and all science, dimensional analysis is a tool to find or check relations among physical quantities by using their dimensions. The dimension of a physical quantity is the combination of the basic physical dimensions which describe it; for example, speed has the dimension length per...
as well as an estimation of the heat capacity for very hot air, by the British physicist G. I. Taylor
Geoffrey Ingram Taylor
Sir Geoffrey Ingram Taylor OM was a British physicist, mathematician and expert on fluid dynamics and wave theory. His biographer and one-time student, George Batchelor, described him as "one of the most notable scientists of this century".-Biography:Taylor was born in St. John's Wood, London...
. Taylor had initially done this highly classified work in mid-1941, and published a paper which included an analysis of the Trinity data fireball when the Trinity photograph data was declassified in 1950 (after the USSR had exploded its own version of this bomb).
Taylor noted that the radius
Radius
In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...
R of the blast should initially depend only on the energy E of the explosion, the time t after the detonation, and the density ρ of the air. The only number having dimensions of length that can be constructed from these quantities is:
Here S is a dimensionless constant having a value approximately equal to 1, since it is low order function of the heat capacity ratio
Heat capacity ratio
The heat capacity ratio or adiabatic index or ratio of specific heats, is the ratio of the heat capacity at constant pressure to heat capacity at constant volume . It is sometimes also known as the isentropic expansion factor and is denoted by \gamma or \kappa . The latter symbol kappa is...
or adiabatic index (γ = Cp/
Cv), which is approximately 1 for all conditions.
Using the picture of the Trinity test shown here (which had been publicly released by the U.S. government and published in Life
Life (magazine)
Life generally refers to three American magazines:*A humor and general interest magazine published from 1883 to 1936. Time founder Henry Luce bought the magazine in 1936 solely so that he could acquire the rights to its name....
magazine), using successive frames or the explosion, Taylor found that R5/t2 is a constant in a given nuclear blast (especially between 0.38 ms after the shock wave has formed, and 1.93 ms before significant energy is lost by thermal radiation). Furthermore, he estimated a value for S numerically at 1.
Thus, with t = 0.025 s and the blast radius was 140 metres, and taking ρ to be 1 kg/m³ (the measured value at Trinity on the day of the test, as opposed to sea level values of approximately 1.3 kg/m³) and solving for E, Taylor obtained that the yield was about 22 kilotons of TNT (90 TJ). This does not take into account the fact that the energy should only be about half this value for a hemispherical blast, but this very simple argument did agree to within 10% with the official value of the bomb's yield in 1950, which was 20 ktonTNT (See G. I. Taylor, Proc. Roy. Soc. London A 200, pp. 235-247 (1950).)
A good approximation to Taylor's constant S for γ below about 2 is: S = [75(γ-1)/8π]1/5.
. The value of the heat capacity ratio
Heat capacity ratio
The heat capacity ratio or adiabatic index or ratio of specific heats, is the ratio of the heat capacity at constant pressure to heat capacity at constant volume . It is sometimes also known as the isentropic expansion factor and is denoted by \gamma or \kappa . The latter symbol kappa is...
here is between the 1.67 of fully dissociated air molecules and the lower value for very hot diatomic air (1.2), and under conditions of an atomic fireball is (coincidentally) close to the S.T.P. (standard) gamma for room temperature air, which is 1.4. This gives the value of Taylor's S constant to be 1.036 for the adiabatic hypershock region where the constant R5/t2 condition holds.
Other methods and controversy
Where this data is not available, as in a number of cases, precise yields have been in dispute, especially when they are tied to questions of politics. The weapons used in the atomic bombings of Hiroshima and NagasakiAtomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...
, for example, were highly individual and very idiosyncratic designs, and gauging their yield retrospectively has been quite difficult. The Hiroshima bomb, "Little Boy
Little Boy
"Little Boy" was the codename of the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon...
", is estimated to have been between 12 ktTNT (a 20% margin of error), while the Nagasaki bomb, "Fat Man
Fat Man
"Fat Man" is the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945. It was the second of the only two nuclear weapons to be used in warfare to date , and its detonation caused the third man-made nuclear explosion. The name also refers more...
", is estimated to be between 18 ktTNT (a 10% margin of error). Such apparently small changes in values can be important when trying to use the data from these bombings as reflective of how other bombs would behave in combat, and also result in differing assessments of how many "Hiroshima bombs" other weapons are equivalent to (for example, the Ivy Mike
Ivy Mike
Ivy Mike was the codename given to the first United States test of a thermonuclear weapon, in which a major part of the explosive yield came from nuclear fusion. It was detonated on November 1, 1952 by the United States at on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy...
hydrogen bomb was equivalent to either 867 or 578 Hiroshima weapons — a rhetorically quite substantial difference — depending on whether one uses the high or low figure for the calculation). Other disputed yields have included the massive Tsar Bomba
Tsar Bomba
Tsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. It was also referred to as Kuz'kina Mat , in this usage meaning "something that has not been seen before"....
, whose yield was claimed between being "only" 50 MtTNT or at a maximum of 57 MtTNT by differing political figures, either as a way for hyping the power of the bomb or as an attempt to undercut it.
See also
- Effects of nuclear explosionsEffects of nuclear explosionsThe energy released from a nuclear weapon detonated in the troposphere can be divided into four basic categories:*Blast—40-50% of total energy*Thermal radiation—30-50% of total energy...
— goes into detail about different effects at different yields
External links
- "What was the yield of the Hiroshima bomb?" (excerpt from official report)
- "General Principles of Nuclear Explosions", Chapter 1 in Samuel Glasstone and Phillip Dolan, eds., The Effects of Nuclear Weapons, 3rd edn. (Washington D.C.: U.S. Department of Defense/U.S. Energy Research and Development Administration, 1977); provides information about the relationship of nuclear yields to other effects (radiation, damage, etc.).
- "THE MAY 1998 POKHRAN TESTS: Scientific Aspects", discusses different methods used to determine the yields of the Indian 1998 tests.
- Discusses some of the controversy over the Indian test yields
- "What are the real yields of India's nuclear tests?" from Carey Sublette's NuclearWeaponArchive.org
- High-Yield Nuclear Detonation Effects Simulator